Comparator Formulae

[WazzaJB]

Hey,

I'm a refrigeration apprentice studying R&AC, I'm also beginning my DofE Gold, as my skills project I am looking to do a bit of software development for the industry as a 6 month project. Long story cut short, I am looking for formulas to calculate saturation temperatures at certain pressures (and vice-versa) like a comparator would. Everywhere I have looked fails to give me a straightforward equation with variables, is this because of the complexity of the equations?

I did find a Visual Basic resource (I will be programming the application in Visual Basic) that seems to have all the functions I would need, but I'd rather program one myself if I knew the equations.

Thanks in advance to anyone who can help,

Wazza.

PS: Here's a link to the VB resource for those who are interested, http://www.boulder.nist.gov/div838/t...rop/REFPROP.VB

[Quality]

iphone app

[WazzaJB]

iphone app

I'm not looking for a comparator, I'm wondering if anyone has/knows the whereabouts of the maths to add it into the application I'm working on....

[Brian_UK]

I knew this subject had come up before and using the site search facility you would have found it as well.

Anyway this is a copy of the post from an earlier thread, it might get you going.

++
If you want the formulae used by DuPont then download this pdf file...

http://www2.dupont.com/Refrigerants/...o_prop_eng.pdf

The above is English units, if you want SI then select from the list here..

http://www2.dupont.com/Refrigerants/...rature.html#pt

[Magoo]

Hi all.
the industry in europe is full of abbreviations. Can nobody speak/type what ever in real language. This is an international forum. I could fire in a lot local stuff from NZ to totally Pizz off everybody, but I am respectful to the global readers.
grump

[Josip]

Hi, WazzaJB

welcome to RE forums .....

Hey,

I'm a refrigeration apprentice studying R&AC, I'm also beginning my DofE Gold, as my skills project I am looking to do a bit of software development for the industry as a 6 month project. Long story cut short, I am looking for formulas to calculate saturation temperatures at certain pressures (and vice-versa) like a comparator would. Everywhere I have looked fails to give me a straightforward equation with variables, is this because of the complexity of the equations?

I did find a Visual Basic resource (I will be programming the application in Visual Basic) that seems to have all the functions I would need, but I'd rather program one myself if I knew the equations.

Thanks in advance to anyone who can help,

Wazza.

PS: Here's a link to the VB resource for those who are interested, http://www.boulder.nist.gov/div838/t...rop/REFPROP.VB

Please check this ....

http://www.refrigeration-engineer.com/forums/showthread.php?21844-NIST-Ref-Prop

http://www.refrigeration-engineer.com/forums/showthread.php?19752-Equation-engineering-solve

http://www.refrigeration-engineer.com/forums/showthread.php?10271-Refrigerant-properties-calculator

http://www.refrigeration-engineer.com/forums/showthread.php?30760-Specific-heat-capacity-for-saturated-vapor-and-liquid

http://www.refrigeration-engineer.co...read.php?9731-Temperature-to-Pressure-Formulas-for-R22-R12-R717-etc


http://www.refrigeration-engineer.co...read.php?3807-Numerical-Methods-for-Engineers-and-Scientists-Second-Edition

http://www.refrigeration-engineer.co...read.php?3916-EES-user


not too much to read but with many useful links and suggestions .... hope to be of some help to you ... good luck ... of course you can make your own investigation of RE forums ....

Best regards, Josip